The invention relates to a surgical instrument as well as to a method of operating a rinsing device of the surgical instrument.
From German published patent application DE 41 39 029 A1 (counterpart: U.S. Pat. No. 5,720,745) a high-frequency surgical device is known that coagulates tissue and is used together with an endoscope. In this procedure an inert gas is conducted to the operation site through a tube that contains an electrode, and a high-frequency (HF) coagulation current is supplied to the electrode and to the tissue, so that between the electrode and the region of tissue there is formed a plasma flux that coagulates the tissue. In order to clean the operation site, a rinsing liquid is applied before, during and after the coagulation treatment, by passage through a working channel of the endoscope. Rinsing of the endoscope optics can also be performed, in order to maintain a clear field of view.
International application publication No. WO 01/08577 discloses a surgical instrument with an electrode constructed as a polypectomy loop. Argon gas is conducted to the operation site as a protective gas, to prevent smoke production while a polyp is being removed by an HF current. A rinsing device to serve the above functions is likewise present.
Many other kinds of surgical apparatus are known, in particular to be used within body cavities (e.g., also laser apparatus), that conduct an inert gas to the treatment region for the purposes mentioned above, and that contain rinsing devices. The construction of all such apparatus is extremely elaborate.
From German Patent DE 34 15 837 C2 a liquid-supplying device for endoscopes is known that comprises an air pump by way of which pressure can be applied to a liquid container, in order to supply the endoscope with rinsing liquid or, alternatively, air. This device, too, has an elaborate construction.
From German published patent application DE 43 32 070 A1 a device for perfusing a body cavity is known in which a rinsing liquid contained in a disposable bag within a pressure container is conducted to the perfusion instrument by air pressure generated by a pressure source. This device is likewise elaborate.
From U.S. Pat. No. 5,785,521 a surgical instrument (in this case an instrument for laser surgery) known having a gas-delivery device to supply an inert gas to a tissue-treatment region and a rinsing device for rinsing a target region. A rinsing stream of rinsing liquid is put under a rinsing pressure by the inert gas supplied by the gas-delivery device. However, in the case of this device the rinsing process cannot be precisely controlled.